With the development of the times, a mobile phone positioning technology has drawn more and more attentions. Both a Global Positioning System (GPS) positioning technology and positioning with a wireless sensor network or another positioning means have limits. In order to achieve higher positioning accuracy, combination of multiple positioning systems for cooperative positioning, i.e. multimode positioning is a direction for future development, and respective advantages may be utilized to achieve higher accuracy and response speed and also cover a wider range to implement seamless and accurate positioning. For example, a satellite positioning system and a mobile communication system are organically combined for mobile phone positioning, and advantages of large coverage area and high open space positioning accuracy of the satellite positioning system and high indoor and dense urban area positioning accuracy of a mobile communication network are fully utilized, so that a market requirement is better met.
For satellite positioning, at least four satellites are required to be found, distance measurement is performed according to time of arrival, then at least four spherical equations or hyperbolic equations are listed according to a distance measurement result, as shown in FIG. 1 and FIG. 2, and the equations are solved to obtain a spatial position. In a room or a dense urban area, a GPS signal is highly attenuated, so that four satellites may not be completely found, GPS positioning may not be implemented, and a positioning function is restricted.
A conventional wireless positioning solution has a main problem of narrow selection range of positioning anchor points only limited to public anchor points such as satellite base stations. In addition, the problem of cellular positioning accuracy may also be caused by factors of Non Line Of Sight (NLOS), multiple paths, channel environment changes and the like in a room, and about this, some research results have been obtained, all usually on the basis of ideal assumptions, in the industry, and a technical solution feasible during a practical application is required to be further deeply researched.